1. Field of the Invention
The present invention relates to a display apparatus, and more particularly, to a display apparatus using an organic electroluminescence (EL) display element.
2. Description of the Related Art
To achieve gray levels in an image displayed on an active matrix organic electroluminescent display apparatus, it is known to divide one frame period into a plurality of subframe periods, and rewrite data on a subframe-by-subframe basis to control emission of each pixel in each subframe. In the case of a color organic electroluminescent display apparatus, the display apparatus includes a plurality of pixels each including three organic electroluminescent elements capable of emitting light of red (R), green (G), and blue (B), respectively, and a white balance adjustment is performed by changing the ratio of luminance among the three organic electroluminescent elements.
U.S. Patent Application Publication No. 2006/0208656 discloses a technique in which timing of turning on organic electroluminescent elements of pixels into a light emission state is fixed for light of R, G, and B colors (hereafter referred to as RGB colors), while timing of turning off into an extinction or no light emission state is varied among the RGB colors to achieve a white color adjustment in each subframe.
To control the timing of turning off the organic electroluminescent elements into the extinction state individually for respective RGB colors, each EL driving circuit needs to include not only a circuit for turning on the corresponding organic electroluminescent element according to data but also a circuit for turning off the organic electroluminescent element. Furthermore, in addition to control lines for writing data in units of rows, three control lines are provided in each row to control transistors for turning off the organic electroluminescent elements of the respective RGB colors.
The provision of such additional control lines results in a reduction in layout space in which circuit elements such as transistors, capacitors, etc., of EL driving circuits are disposed, and thus it becomes difficult to realize a display apparatus with a small size and/or high resolution.
In view of the above, the present invention provides a display apparatus capable of adjusting white balance with a minimized number of circuit elements such as control lines, transistors forming an EL driving circuit, etc.